Sharing an iTunes library with multiple user accounts

I have a large music library (>200GB) and I want to have the library accesssable to myself and my 2 sons. We each have our own Windows account and I set there iTunes instances up to not copy files to their iTunes music folder. Music is working ok, but podcasts are a problem. When I log into iTunes, there are exclamation marks next to all moyt podcasts now.

Is there a way to do this that will allow us to share all the music, and have our own podcasts? If not, how can I at least have a common podcast directory for all 3 of us.

TIA